1 files changed, 103 insertions, 34 deletions

diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index c2689f4ba8d..e15a9eb2908 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -10,81 +10,95 @@
  */
 
 #include <linux/module.h>
+#include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
-#include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <net/pkt_sched.h>
 
 /* 1 band FIFO pseudo-"scheduler" */
 
-struct fifo_sched_data
+static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
-	u32 limit;
-};
+	if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit))
+		return qdisc_enqueue_tail(skb, sch);
 
-static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
-{
-	struct fifo_sched_data *q = qdisc_priv(sch);
+	return qdisc_reshape_fail(skb, sch);
+}
 
-	if (likely(sch->qstats.backlog + skb->len <= q->limit))
+static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch)
+{
+	if (likely(skb_queue_len(&sch->q) < sch->limit))
 		return qdisc_enqueue_tail(skb, sch);
 
 	return qdisc_reshape_fail(skb, sch);
 }
 
-static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
-	struct fifo_sched_data *q = qdisc_priv(sch);
-
-	if (likely(skb_queue_len(&sch->q) < q->limit))
+	if (likely(skb_queue_len(&sch->q) < sch->limit))
 		return qdisc_enqueue_tail(skb, sch);
 
-	return qdisc_reshape_fail(skb, sch);
+	/* queue full, remove one skb to fulfill the limit */
+	__qdisc_queue_drop_head(sch, &sch->q);
+	sch->qstats.drops++;
+	qdisc_enqueue_tail(skb, sch);
+
+	return NET_XMIT_CN;
 }
 
-static int fifo_init(struct Qdisc *sch, struct rtattr *opt)
+static int fifo_init(struct Qdisc *sch, struct nlattr *opt)
 {
-	struct fifo_sched_data *q = qdisc_priv(sch);
+	bool bypass;
+	bool is_bfifo = sch->ops == &bfifo_qdisc_ops;
 
 	if (opt == NULL) {
-		u32 limit = sch->dev->tx_queue_len ? : 1;
+		u32 limit = qdisc_dev(sch)->tx_queue_len ? : 1;
 
-		if (sch->ops == &bfifo_qdisc_ops)
-			limit *= sch->dev->mtu;
+		if (is_bfifo)
+			limit *= psched_mtu(qdisc_dev(sch));
 
-		q->limit = limit;
+		sch->limit = limit;
 	} else {
-		struct tc_fifo_qopt *ctl = RTA_DATA(opt);
+		struct tc_fifo_qopt *ctl = nla_data(opt);
 
-		if (RTA_PAYLOAD(opt) < sizeof(*ctl))
+		if (nla_len(opt) < sizeof(*ctl))
 			return -EINVAL;
 
-		q->limit = ctl->limit;
+		sch->limit = ctl->limit;
 	}
 
+	if (is_bfifo)
+		bypass = sch->limit >= psched_mtu(qdisc_dev(sch));
+	else
+		bypass = sch->limit >= 1;
+
+	if (bypass)
+		sch->flags |= TCQ_F_CAN_BYPASS;
+	else
+		sch->flags &= ~TCQ_F_CAN_BYPASS;
 	return 0;
 }
 
 static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
-	struct fifo_sched_data *q = qdisc_priv(sch);
-	struct tc_fifo_qopt opt = { .limit = q->limit };
+	struct tc_fifo_qopt opt = { .limit = sch->limit };
 
-	RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
+		goto nla_put_failure;
 	return skb->len;
 
-rtattr_failure:
+nla_put_failure:
 	return -1;
 }
 
-struct Qdisc_ops pfifo_qdisc_ops = {
+struct Qdisc_ops pfifo_qdisc_ops __read_mostly = {
 	.id		=	"pfifo",
-	.priv_size	=	sizeof(struct fifo_sched_data),
+	.priv_size	=	0,
 	.enqueue	=	pfifo_enqueue,
 	.dequeue	=	qdisc_dequeue_head,
-	.requeue	=	qdisc_requeue,
+	.peek		=	qdisc_peek_head,
 	.drop		=	qdisc_queue_drop,
 	.init		=	fifo_init,
 	.reset		=	qdisc_reset_queue,
@@ -92,13 +106,14 @@ struct Qdisc_ops pfifo_qdisc_ops = {
 	.dump		=	fifo_dump,
 	.owner		=	THIS_MODULE,
 };
+EXPORT_SYMBOL(pfifo_qdisc_ops);
 
-struct Qdisc_ops bfifo_qdisc_ops = {
+struct Qdisc_ops bfifo_qdisc_ops __read_mostly = {
 	.id		=	"bfifo",
-	.priv_size	=	sizeof(struct fifo_sched_data),
+	.priv_size	=	0,
 	.enqueue	=	bfifo_enqueue,
 	.dequeue	=	qdisc_dequeue_head,
-	.requeue	=	qdisc_requeue,
+	.peek		=	qdisc_peek_head,
 	.drop		=	qdisc_queue_drop,
 	.init		=	fifo_init,
 	.reset		=	qdisc_reset_queue,
@@ -106,6 +121,60 @@ struct Qdisc_ops bfifo_qdisc_ops = {
 	.dump		=	fifo_dump,
 	.owner		=	THIS_MODULE,
 };
-
 EXPORT_SYMBOL(bfifo_qdisc_ops);
-EXPORT_SYMBOL(pfifo_qdisc_ops);
+
+struct Qdisc_ops pfifo_head_drop_qdisc_ops __read_mostly = {
+	.id		=	"pfifo_head_drop",
+	.priv_size	=	0,
+	.enqueue	=	pfifo_tail_enqueue,
+	.dequeue	=	qdisc_dequeue_head,
+	.peek		=	qdisc_peek_head,
+	.drop		=	qdisc_queue_drop_head,
+	.init		=	fifo_init,
+	.reset		=	qdisc_reset_queue,
+	.change		=	fifo_init,
+	.dump		=	fifo_dump,
+	.owner		=	THIS_MODULE,
+};
+
+/* Pass size change message down to embedded FIFO */
+int fifo_set_limit(struct Qdisc *q, unsigned int limit)
+{
+	struct nlattr *nla;
+	int ret = -ENOMEM;
+
+	/* Hack to avoid sending change message to non-FIFO */
+	if (strncmp(q->ops->id + 1, "fifo", 4) != 0)
+		return 0;
+
+	nla = kmalloc(nla_attr_size(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
+	if (nla) {
+		nla->nla_type = RTM_NEWQDISC;
+		nla->nla_len = nla_attr_size(sizeof(struct tc_fifo_qopt));
+		((struct tc_fifo_qopt *)nla_data(nla))->limit = limit;
+
+		ret = q->ops->change(q, nla);
+		kfree(nla);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(fifo_set_limit);
+
+struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
+			       unsigned int limit)
+{
+	struct Qdisc *q;
+	int err = -ENOMEM;
+
+	q = qdisc_create_dflt(sch->dev_queue, ops, TC_H_MAKE(sch->handle, 1));
+	if (q) {
+		err = fifo_set_limit(q, limit);
+		if (err < 0) {
+			qdisc_destroy(q);
+			q = NULL;
+		}
+	}
+
+	return q ? : ERR_PTR(err);
+}
+EXPORT_SYMBOL(fifo_create_dflt);